456 J. E. BEADFORD AND H. G. Pl.lMMEE. 



the organism is shown in figs. 11 — 17. The first step is a 

 general increase in the size of the organism ; the micronucleus 

 first enlarges, and then the macronucleus, which becomes 

 also very distinct (this is well shown in figs. 11 — 13) ; the 

 micronnclens lengthens out and divides into two, to the 

 second of which a new undulating membrane, which is by 

 this time developed, is attached (figs. 12 and 17) ; the macro- 

 nucleus then divides (figs. 14 — 17), and a white line is seen 

 extending down the long axis of the body (figs. 14 — 16) ; 

 eventually the organisms separate into two fully formed 

 Trypanosomata. The order of the division is in general 

 this : — firstly the micronucleus, then the undulating mem- 

 brane, then the macronucleus, and lastly the protoplasm. 



In fig. 17 is shown the division of one of the large, hyaline 

 variety of the organisn], which has been described above. In 

 this kind the process is exactly similar to that in the ordinary 

 variety, only it is much more distinct, on account of the 

 larger size of the organism, and its clearer staining. 



IV. Conjugation between the Adult Teypanosomata 



Beucii. 



In the blood of the rat, and of all the animals we have 

 examined (mouse, dog, cat, rabbit, guinea-pig, horse, mule, 

 pig, spring-bok, goat), forms have been seen, such as those 

 shown in figs. 18 — 23, which we think can only be interpreted 

 as conjugations. The organisms can be seen in the living 

 blood joined together by their blunt ends, and moving about 

 in this state by their flagellated extremities, the joined parts 

 remaining motionless. In stained specimens they are found 

 as figured, and the only difference in these is the position of 

 the micronuclei. At first, after the bodies have joined, these 

 micronuclei are in their normal position at the usual distance 

 from the blunt end of each organism (fig. 18), then they are 

 seen to approximate to each other (fig. 19), and then they 

 get still nearer and nearer (figs. 20 and 21), until they 

 become fused into one micronucleus (fig. 22). Several other 



